Moving beyond the national lung screening trial: discussing strategies for implementation of lung cancer screening programs

Cost-Effectiveness Analyses of Lung Cancer Screening Using Low-Dose Computed Tomography: A Systematic Review Assessing Strategy Comparison and Risk Stratification

OBJECTIVES

Our first study objective was to assess the range of lung cancer screening intervals compared within cost-effectiveness analyses (CEAs) of low-dose computed tomography (LDCT) and to examine the implications for the strategies identified as optimally cost effective; the second objective was to examine if and how risk subgroup-specific policies were considered.

METHODS

PubMed, Embase and Web of Science were searched for model-based CEAs of LDCT lung screening. The retrieved studies were assessed to examine if the analyses considered sufficient strategy variation to permit incremental estimation of cost effectiveness. Regarding risk selection, we examined if analyses considered alternative risk strata in separate analyses or as alternative risk-based eligibility criteria for screening.

RESULTS

The search identified 33 eligible CEAs, 23 of which only considered one screening frequency. Of the 10 analyses considering multiple screening intervals, only 4 included intervals longer than 2 years. Within the 10 studies considering multiple intervals, the optimal policy choice would differ in 5 if biennial intervals or longer had not been considered. Nineteen studies conducted risk subgroup analyses, 12 of which assumed that subgroup-specific policies were possible and 7 of which assumed that a common screening policy applies to all those screened.

CONCLUSIONS

The comparison of multiple strategies is recognised as good practice in CEA when seeking optimal policies. Studies that do include multiple intervals indicate that screening intervals longer than 1 year can be relevant. The omission of intervals of 2 years or longer from CEAs of LDCT screening could lead to the adoption of sub-optimal policies. There also is scope for greater consideration of risk-stratified policies which tailor screening intensity to estimated disease risk. Policy makers should take care when interpreting current evidence before implementing lung screening.

NCCN Guidelines® Insights: Lung Cancer Screening, Version 1.2022

The NCCN Guidelines for Lung Cancer Screening recommend criteria for selecting individuals for screening and provide recommendations for evaluation and follow-up of lung nodules found during initial and subsequent screening. These NCCN Guidelines Insights focus on recent updates to the NCCN Guidelines for Lung Cancer Screening.

Cost-effectiveness of Low-Dose Computed Tomography With a Plasma-Based Biomarker for Lung Cancer Screening in China

IMPORTANCE

China, which has one-third of the worldwide smoking population, has a substantial cancer burden, with lung cancer being the leading cause of cancer-related death. The effectiveness of lung cancer screening for mortality reduction has been confirmed, but the cost-effectiveness of diverse screening modalities remains unclear.

OBJECTIVE

To compare the cost-effectiveness of low-dose computed tomography (LDCT) with a biomarker (micro-RNA signature classifier [MSC]) with that of LDCT alone by screening interval and cumulative smoking exposure.

DESIGN, SETTING, AND PARTICIPANTS

In this economic evaluation, a comparative cost-effectiveness analysis used Markov state transition models that simulated the 1947 to 1971 China birth cohort. Simulated individuals in 8 cohorts of 10 000 entered the study between ages 50 and 74 years and were followed up until death or age 79 years, corresponding to a study period from January 1, 2021, to December 31, 2050. The model was run with a cycle length of 1 year. All the transition probabilities were validated, and health utility values were extracted from published literature. Cost parameters were derived from the databases of local medical insurance bureaus.

MAIN OUTCOMES AND MEASURES

Primary outcomes included life-years, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs) with future costs and outcomes discounted by 5%. Screening strategies with a mean ICER less than Chinese yuan (CNY) 212 676 per QALY gained were deemed to be cost-effective. The cost-effectiveness of 7 alternative screening strategies with a screening starting age of 50 years, minimum cumulative smoking exposure of 20 vs 30 pack-years, and screening interval of annual vs 1 time was estimated, including the 2021 China guideline-recommended strategy (LDCT, annual, 30 pack-years) and the 2018 China guideline-recommended strategy (LDCT, annual, 20 pack-years).

RESULTS

In a simulated population of 80 000 individuals, the conjunctive LDCT and MSC screening strategy was estimated to obtain an ICER of CNY -793 995.17 to 254 417.46 (minimum cumulative smoking exposure, 20-30 pack-years) per QALY gained compared with LDCT screening alone. China's 2021 guideline-recommended strategy was not cost-effective compared with the 2018 guideline-recommended strategy, with higher costs and fewer QALYs gained; the QALY loss ranged from 0.02 to 0.15 per person and the increase in cost ranged from CNY 945.89 to CNY 5131.29 per person. LDCT and MSC screening beginning at age 70 to 74 years in individuals with a 20 pack-year smoking history was the most cost-effective strategy, with an ICER of CNY -793 995.17 per QALY gained. Lowering the minimum cumulative smoking exposure for screening from 30 to 20 pack-years and maintaining annual screening were associated with greater cost savings regardless of the screening tool.

CONCLUSIONS AND RELEVANCE

This economic evaluation found that China's 2018 recommendation for lung cancer screening was more cost-effective than the 2021 recommendation. Moreover, the cost-effectiveness of lung cancer screening was improved when MSC was included with LDCT. These findings may be useful for the modification of guidelines for lung cancer screening.

Prospective Study of Spatial Distribution of Missed Lung Nodules by Readers in CT Lung Screening Using Computer-assisted Detection

PURPOSE

To evaluate the spatial patterns of missed lung nodules in a real-life routine screening environment.

MATERIALS AND METHODS

In a screening institute, 4,822 consecutive adults underwent chest CT, and each image set was independently interpreted by two radiologists in three steps: (1) independently interpreted without computer-assisted detection (CAD) software, (2) independently referred to the CAD results, (3) determined by the consensus of the two radiologists. The locations of nodules and the detection performance data were semi-automatically collected using a CAD server integrated into the reporting system. Fisher's exact test was employed for evaluating findings in different lung divisions. Probability maps were drawn to illustrate the spatial distribution of radiologists' missed nodules.

RESULTS

Radiologists significantly tended to miss lung nodules in the bilateral hilar divisions (p < 0.01). Some radiologists had their own spatial pattern of missed lung nodules.

CONCLUSION

Radiologists tend to miss lung nodules present in the hilar regions significantly more often than in the rest of the lung.

Real-world Clinical Implementation of Lung Cancer Screening-Evaluating Processes to Improve Screening Guidelines-Concordance

BACKGROUND

Lung cancer screening (LCS) requires complex processes to identify eligible patients, provide appropriate follow-up, and manage findings. It is unclear whether LCS in real-world clinical settings will realize the same benefits as the National Lung Screening Trial (NLST).

OBJECTIVE

To evaluate the impact of process modifications on compliance with LCS guidelines during LCS program implementation, and to compare patient characteristics and outcomes with those in NLST.

DESIGN

Retrospective cohort study.

SETTING

Kaiser Permanente Colorado (KPCO), a non-profit integrated healthcare system.

PATIENTS

A total of 3375 patients who underwent a baseline lung cancer screening low-dose computed tomography (S-LDCT) scan between May 2014 and June 2017.

MEASUREMENTS

Among those receiving an S-LDCT, proportion who met guidelines-based LCS eligibility criteria before and after LCS process modifications, differences in patient characteristics and outcomes between KPCO LCS patients and the NLST cohort, and factors associated with a positive screen.

RESULTS

After modifying LCS eligibility confirmation processes, patients receiving S-LDCT who met guidelines-based LCS eligibility criteria increased from 45.6 to 92.7% (P < 0.001). Prior to changes, patients were older (68 vs. 67 years; P = 0.001), less likely to be current smokers (51.3% vs. 52.5%; P < 0.001), and less likely to have a ≥ 30-pack-year smoking history (50.0% vs. 95.3%; P < 0.001). Compared with NLST participants, KPCO LCS patients were older (67 vs. 60 years; P < 0.001), more likely to currently smoke (52.3% vs. 48.1%; P < 0.001), and more likely to have pulmonary disease. Among those with a positive baseline S-LDCT, the lung cancer detection rate was higher at KPCO (9.4% vs. 3.8%; P < 0.001) and was positively associated with prior pulmonary disease.

CONCLUSION

Adherence to LCS guidelines requires eligibility confirmation procedures. Among those with a positive baseline S-LDCT, comorbidity burden and lung cancer detection rates were notably higher than in NLST, suggesting that the study of long-term outcomes in patients undergoing LCS in real-world clinical settings is warranted.

Lung Cancer Screening, Version 3.2018, NCCN Clinical Practice Guidelines in Oncology

Lung cancer is the leading cause of cancer-related mortality in the United States and worldwide. Early detection of lung cancer is an important opportunity for decreasing mortality. Data support using low-dose computed tomography (LDCT) of the chest to screen select patients who are at high risk for lung cancer. Lung screening is covered under the Affordable Care Act for individuals with high-risk factors. The Centers for Medicare & Medicaid Services (CMS) covers annual screening LDCT for appropriate Medicare beneficiaries at high risk for lung cancer if they also receive counseling and participate in shared decision-making before screening. The complete version of the NCCN Guidelines for Lung Cancer Screening provides recommendations for initial and subsequent LDCT screening and provides more detail about LDCT screening. This manuscript focuses on identifying patients at high risk for lung cancer who are candidates for LDCT of the chest and on evaluating initial screening findings.

The Roles of MicroRNA in Lung Cancer

Lung cancer is the most devastating malignancy in the world. Beyond genetic research, epigenomic studies—especially investigations of microRNAs—have grown rapidly in quantity and quality in the past decade. This has enriched our understanding about basic cancer biology and lit up the opportunities for potential therapeutic development. In this review, we summarize the involvement of microRNAs in lung cancer carcinogenesis and behavior, by illustrating the relationship to each cancer hallmark capability, and in addition, we briefly describe the clinical applications of microRNAs in lung cancer diagnosis and prognosis. Finally, we discuss the potential therapeutic use of microRNAs in lung cancer.

Monitoring Lung Cancer Screening Use and Outcomes at Four Cancer Research Network Sites

RATIONALE

Lung cancer screening registries can monitor screening outcomes and improve quality of care.

OBJECTIVES

To describe nascent lung cancer screening programs and share efficient data collection approaches for mandatory registry reporting in four integrated health care systems of the National Cancer Institute-funded Cancer Research Network.

METHODS

We documented the distinctive characteristics of lung cancer screening programs, and we provide examples of strategies to facilitate data collection and describe early challenges and possible solutions. In addition, we report preliminary data on use and outcomes of screening with low-dose computed tomography at each of the participating sites.

RESULTS

Programs varied in approaches to confirming patient eligibility, ordering screening low-dose computed tomographic scans, and coordinating follow-up care. Most data elements were collected from structured fields in electronic health records, but sites also made use of standardized order templates, local procedure codes, identifiable hashtags in radiology reports, and natural language processing algorithms. Common challenges included incomplete documentation of tobacco smoking history, difficulty distinguishing between scans performed for screening versus diagnosis or surveillance, and variable adherence with use of standardized templates. Adherence with eligibility criteria as well as the accuracy and completeness of data collection appeared to depend at least partly on availability of personnel and other resources to support the successful implementation of screening.

CONCLUSIONS

To maximize the effectiveness of lung cancer screening, minimize the burden of data collection, and facilitate research and quality improvement, clinical workflow and information technology should be purposefully designed to ensure that patients meet eligibility criteria and receive appropriate follow-up testing.

New recommendation and coverage of low-dose computed tomography for lung cancer screening: uptake has increased but is still low

Background

In 2013, the US Preventive Services Task Force (USPSTF) issued recommendations for low-dose computed tomography for lung cancer screening (LDCT-LCS), but there continues to be a dearth of information on the adoption of LDCT-LCS in healthcare systems. Using a multilevel perspective, our study aims to assess referrals for LDCT-LCS and identify facilitators and barriers to adoption following recent policy changes.

Methods

A retrospective analysis of electronic medical record data from patients aged 55–80 years with no history of lung cancer who visited a primary care provider in a large healthcare system in California during 2010–2016 (1,572,538 patient years). Trends in documentation of smoking history, number of eligible patients, and lung cancer screening orders were assessed. Using Hierarchical Generalized Linear Models, we also evaluated provider-level and patient-level factors associated with lung cancer screening orders among 970 primary care providers and 12,801 eligible patients according to USPSTF guidelines between January 1st, 2014 and December 31st, 2016.

Results

Documentation of smoking history to determine eligibility (59.2% in 2010 to 77.8% in 2016) and LDCT-LCS orders (0% in 2010 to 7.3% in 2016) have increased since USPSTF guidelines. Patient factors associated with increased likelihood of lung cancer screening orders include: younger patient age (78–80 vs. 55–64 years old: OR, 0.4; 95% CI, 0.3–0.7), Asian race (vs. Non-Hispanic White: OR, 1.6; 95% CI, 1.1–2.4), reported current smoking (vs. former smoker: OR, 1.7; 95% CI, 1.4–2.0), no severe comorbidity (severe vs. no major comorbidity: OR = 0.2, 95% CI = 0.1–0.3; moderate vs. no major comorbidity: OR = 0.5; 95% CI = 0.4–0.7), and making a visit to own primary care provider (vs. other primary care providers: OR, 2.4; 95% CI, 1.7–3.4). Appropriate referral for lung cancer screening varies considerably across primary care providers. Provider factors include being a female physician (vs. male: OR, 1.6; 95% CI, 1.1–2.3) and receiving medical training in the US (foreign vs. US medical school graduates: OR = 0.4, 95% CI = 0.3–0.7).

Conclusions

Future interventions to improve lung cancer screening may be more effective if they focus on accurate documentation of smoking history and target former smokers who do not regularly see their own primary care providers.

Serum and blood based biomarkers for lung cancer screening: a systematic review

Background

Lung cancer is the second most common cancer and the leading cause of cancer death for both men and women. Although low-dose CT (LDCT) is recommended for lung cancer screening in high-risk populations and may decrease lung cancer mortality, there is a need to improve the accuracy of lung cancer screening to decrease over-diagnosis and morbidity. Blood and serum-based biomarkers, including EarlyCDT-lung and microRNA based biomarkers, are promising adjuncts to LDCT in lung cancer screening.

We evaluated the diagnostic performance of EarlyCDT-lung, micro-RNA signature classifier (MSC), and miR-test, and their impact on lung cancer-related mortality and all-cause mortality.

Methods

References were identified using searches of PubMed, EMBASE, and Ovid Medline® from January 2000 to November 2015. Phase three or greater studies in the English language evaluating the diagnostic performance of EarlyCDT-lung, MSC, and miR-test were selected for inclusion.

Results

Three phase 3 studies were identified, one evaluating EarlyCDT-lung, one evaluating miR-Test, and one evaluating MSC respectively. No phase 4 or 5 studies were identified. All three biomarker assays show promise for the detection of lung cancer. MSC shows promise when used in conjunction with LDCT for lung cancer detection, achieving a positive likelihood ratio of 18.6 if both LDCT and MSC are positive, and a negative likelihood ratio of 0.03 if both LDCT and MSC are negative. However, there is a paucity of high-quality studies that can guide clinical implementation.

Conclusions

There is currently no high quality evidence to support or guide the implementation of these biomarkers in clinical practice. Reports of further research at stages four and five for these, and other promising methods, is required.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4024-3) contains supplementary material, which is available to authorized users.

Risk-Targeted Lung Cancer Screening: A Cost-Effectiveness Analysis

BACKGROUND

Targeting low-dose computed tomography (LDCT) for lung cancer screening to persons at highest risk for lung cancer mortality has been suggested to improve screening efficiency.

OBJECTIVE

To quantify the value of risk-targeted selection for lung cancer screening compared with National Lung Screening Trial (NLST) eligibility criteria.

DESIGN

Cost-effectiveness analysis using a multistate prediction model.

DATA SOURCES

NLST.

TARGET POPULATION

Current and former smokers eligible for lung cancer screening.

TIME HORIZON

Lifetime.

PERSPECTIVE

Health care sector.

INTERVENTION

Risk-targeted versus NLST-based screening.

OUTCOME MEASURES

Incremental 7-year mortality, life expectancy, quality-adjusted life-years (QALYs), costs, and cost-effectiveness of screening with LDCT versus chest radiography at each decile of lung cancer mortality risk.

RESULTS OF BASE-CASE ANALYSIS

Participants at greater risk for lung cancer mortality were older and had more comorbid conditions and higher screening-related costs. The incremental lung cancer mortality benefits during the first 7 years ranged from 1.2 to 9.5 lung cancer deaths prevented per 10 000 person-years for the lowest to highest risk deciles, respectively (extreme decile ratio, 7.9). The gradient of benefits across risk groups, however, was attenuated in terms of life-years (extreme decile ratio, 3.6) and QALYs (extreme decile ratio, 2.4). The incremental cost-effectiveness ratios (ICERs) were similar across risk deciles ($75 000 per QALY in the lowest risk decile to $53 000 per QALY in the highest risk decile). Payers willing to pay $100 000 per QALY would pay for LDCT screening for all decile groups.

RESULTS OF SENSITIVITY ANALYSIS

Alternative assumptions did not substantially alter our findings.

LIMITATION

Our model did not account for all correlated differences between lung cancer mortality risk and quality of life.

CONCLUSIONS

Although risk targeting may improve screening efficiency in terms of early lung cancer mortality per person screened, the gains in efficiency are attenuated and modest in terms of life-years, QALYs, and cost-effectiveness.

PRIMARY FUNDING SOURCE

National Institutes of Health (U01NS086294).

Readiness for Implementation of Lung Cancer Screening. A National Survey of Veterans Affairs Pulmonologists

RATIONALE

To mitigate the potential harms of screening, professional societies recommend that lung cancer screening be conducted in multidisciplinary programs with the capacity to provide comprehensive care, from screening through pulmonary nodule evaluation to treatment of screen-detected cancers. The degree to which this standard can be met at the national level is unknown.

OBJECTIVES

To assess the readiness of clinical facilities in a national healthcare system for implementation of comprehensive lung cancer screening programs, as compared with the ideal described in policy recommendations.

METHODS

This was a cross-sectional, self-administered survey of staff pulmonologists in pulmonary outpatient clinics in Veterans Health Administration facilities.

MEASUREMENTS AND MAIN RESULTS

The facility-level response rate was 84.1% (106 of 126 facilities with pulmonary clinics); 88.7% of facilities showed favorable provider perceptions of the evidence for lung cancer screening, and 73.6% of facilities had a favorable provider-perceived local context for screening implementation. All elements of the policy-recommended infrastructure for comprehensive screening programs were present in 36 of 106 facilities (34.0%); the most common deficiencies were the lack of on-site positron emission tomography scanners or radiation oncology services. Overall, 26.5% of Veterans Health Administration facilities were ideally prepared for lung cancer screening implementation (44.1% if the policy recommendations for on-site positron emission tomography scanners and radiation oncology services were waived).

CONCLUSIONS

Many facilities may be less than ideally positioned for the implementation of comprehensive lung cancer screening programs. To ensure safe, effective screening, hospitals may need to invest resources or coordinate care with facilities that can offer comprehensive care for screening through downstream evaluation and treatment of screen-detected cancers.

Geographical Variation and Factors Associated with Non-Small Cell Lung Cancer in Manitoba

Background

Screening decreases non-small cell lung cancer (NSCLC) deaths and is recommended by the Canadian Task Force on Preventive Health Care. We investigated risk factor prevalence and NSCLC incidence at a small region level to inform resource allocation for lung cancer screening.

Methods

NSCLC diagnoses were obtained from the Canadian Cancer Registry, then geocoded to 283 small geographic areas (SGAs) in Manitoba. Sociodemographic characteristics of SGAs were obtained from the 2006 Canadian Census and Canadian Community Health Survey. Geographical variation was modelled using a Bayesian spatial Poisson model.

Results

NSCLC incidence in SGAs ranged from 1 to 343 cases per 100,000 population per year. The highest incidence rates were in the Southeastern, Southwestern, and Central regions of Manitoba, while most of Northern Manitoba had lower rates. Poisson regression suggested areas with higher proportions of Aboriginal people and higher average income, and immigrants had lower NSCLC incidence whereas areas with higher proportions of smokers had higher incidence.

Conclusion

On an SGA level, smoking rates remain the most significant factor driving NSCLC incidence. Socioeconomic status and proportions of immigrants or Aboriginal peoples independently impact NSCLC rates. We have identified SGAs in Manitoba to target in policy and infrastructure planning for lung cancer screening.

Lung Cancer Screening Update

Since the release of the US Preventive Services Task Force and Centers for Medicare and Medicaid Services recommendations for lung cancer screening, low-dose chest computed tomography screening has moved from the research arena to clinical practice. Lung cancer screening programs must reach beyond image acquisition and interpretation and engage in a multidisciplinary effort of clinical shared decision-making, standardization of imaging and nodule management, smoking cessation, and patient follow-up. Standardization of radiologic reports and nodule management will systematize patient care, provide quality assurance, further reduce harm, and contain health care costs. Although the National Lung Screening Trial results and eligibility criteria of a heavy smoking history are the foundation for the standard guidelines for low-dose chest computed tomography screening in the United States, currently only 27% of patients diagnosed with lung cancer would meet US lung cancer screening recommendations. Current and future efforts must be directed to better delineate those patients who would most benefit from screening and to ensure that the benefits of screening reach all socioeconomic strata and racial and ethnic minorities. Further optimization of lung cancer screening program design and patient eligibility will assure that lung cancer screening benefits will outweigh the potential risks to our patients.

Effects of Iterative Reconstruction Algorithms on Computer-assisted Detection (CAD) Software for Lung Nodules in Ultra-low-dose CT for Lung Cancer Screening

RATIONALE AND OBJECTIVES

This study aimed to evaluate the effects of iterative reconstruction (IR) algorithms on computer-assisted detection (CAD) software for lung nodules in ultra-low-dose computed tomography (ULD-CT) for lung cancer screening.

MATERIALS AND METHODS

We selected 85 subjects who underwent both a low-dose CT (LD-CT) scan and an additional ULD-CT scan in our lung cancer screening program for high-risk populations. The LD-CT scans were reconstructed with filtered back projection (FBP; LD-FBP). The ULD-CT scans were reconstructed with FBP (ULD-FBP), adaptive iterative dose reduction 3D (AIDR 3D; ULD-AIDR 3D), and forward projected model-based IR solution (FIRST; ULD-FIRST). CAD software for lung nodules was applied to each image dataset, and the performance of the CAD software was compared among the different IR algorithms.

RESULTS

The mean volume CT dose indexes were 3.02 mGy (LD-CT) and 0.30 mGy (ULD-CT). For overall nodules, the sensitivities of CAD software at 3.0 false positives per case were 78.7% (LD-FBP), 9.3% (ULD-FBP), 69.4% (ULD-AIDR 3D), and 77.8% (ULD-FIRST). Statistical analysis showed that the sensitivities of ULD-AIDR 3D and ULD-FIRST were significantly higher than that of ULD-FBP (P < .001).

CONCLUSIONS

The performance of CAD software in ULD-CT was improved by using IR algorithms. In particular, the performance of CAD in ULD-FIRST was almost equivalent to that in LD-FBP.

Screening for lung cancer: A systematic review and meta-analysis

OBJECTIVES

To examine evidence on benefits and harms of screening average to high-risk adults for lung cancer using chest radiology (CXR), sputum cytology (SC) and low-dose computed tomography (LDCT).

METHODS

This systematic review was conducted to provide up to date evidence for Canadian Task Force on Preventive Health Care (CTFPHC) lung cancer screening guidelines. Four databases were searched to March 31, 2015 along with utilizing a previous Cochrane review search. Randomized trials reporting benefits were included; any design was included for harms. Meta-analyses were performed if possible. PROSPERO #CRD42014009984.

RESULTS

Thirty-four studies were included. For lung cancer mortality there was no benefit of CXR screening, with or without SC. Pooled results from three small trials comparing LDCT to usual care found no significant benefits for lung cancer mortality. One large high quality trial showed statistically significant reductions of 20% in lung cancer mortality over a follow-up of 6.5years, for LDCT compared with CXR. LDCT screening was associated with: overdiagnosis of 10.99-25.83%; 11.18 deaths and 52.03 patients with major complications per 1000 undergoing invasive follow-up procedures; median estimate for false positives of 25.53% for baseline/once-only screening and 23.28% for multiple rounds; and 9.74 and 5.28 individuals per 1000 screened, with benign conditions underwent minor and major invasive follow-up procedures.

CONCLUSION

The evidence does not support CXR screening with or without sputum cytology for lung cancer. High quality evidence showed that in selected high-risk individuals, LDCT screening significantly reduced lung cancer mortality and all-cause mortality. However, for its implementation at a population level, the current evidence warrants the development of standardized practices for screening with LDCT and follow-up invasive testing to maximize accuracy and reduce potential associated harms.

Risk factors assessment and risk prediction models in lung cancer screening candidates

From February 2015, low-dose computed tomography (LDCT) screening entered the armamentarium of diagnostic tools broadly available to individuals at high-risk of developing lung cancer. While a huge number of pulmonary nodules are identified, only a small fraction turns out to be early lung cancers. The majority of them constitute a variety of benign lesions. Although it entails a burden of the diagnostic work-up, the undisputable benefit emerges from: (I) lung cancer diagnosis at earlier stages (stage shift); (II) additional findings enabling the implementation of a preventive action beyond the realm of thoracic oncology. This review presents how to utilize the risk factors from distinct categories such as epidemiology, radiology and biomarkers to target the fraction of population, which may benefit most from the introduced screening modality.

An official American Thoracic Society/American College of Chest Physicians policy statement: implementation of low-dose computed tomography lung cancer screening programs in clinical practice

RATIONALE

Annual low-radiation-dose computed tomography (LDCT) screening for lung cancer has been shown to reduce lung cancer mortality among high-risk individuals and is now recommended by multiple organizations. However, LDCT screening is complex, and implementation requires careful planning to ensure benefits outweigh harms. Little guidance has been provided for sites wishing to develop and implement lung cancer screening programs.

OBJECTIVES

To promote successful implementation of comprehensive LDCT screening programs that are safe, effective, and sustainable.

METHODS

The American Thoracic Society (ATS) and American College of Chest Physicians (ACCP) convened a committee with expertise in lung cancer screening, pulmonary nodule evaluation, and implementation science. The committee reviewed the evidence from systematic reviews, clinical practice guidelines, surveys, and the experience of early-adopting LDCT screening programs and summarized potential strategies to implement LDCT screening programs successfully.

MEASUREMENTS AND MAIN RESULTS

We address steps that sites should consider during the main three phases of developing an LDCT screening program: planning, implementation, and maintenance. We present multiple strategies to implement the nine core elements of comprehensive lung cancer screening programs enumerated in a recent ACCP/ATS statement, which will allow sites to select the strategy that best fits with their local context and workflow patterns. Although we do not comment on cost-effectiveness of LDCT screening, we outline the necessary costs associated with starting and sustaining a high-quality LDCT screening program.

CONCLUSIONS

Following the strategies delineated in this policy statement may help sites to develop comprehensive LDCT screening programs that are safe and effective.

Why and how would we implement a lung cancer screening program?

For decades, lung cancer has been the most common cancer in terms of both incidence and mortality. There has been very little improvement in the prognosis of lung cancer. Early treatment following early diagnosis is considered to have potential for development. The National Lung Screening Trial (NLST), a large, well-designed randomized controlled trial, evaluated low-dose computed tomography (LDCT) as a screening tool for lung cancer. Compared with chest X-ray, annual LDCT screening reduced death from lung cancer and overall mortality by 20 and 6.7 %, respectively, in high-risk people aged 55–74 years. Several smaller trials of LDCT screening are under way, but none are sufficiently powered to detect a 20 % reduction in lung cancer death. Thus, it is very unlikely that the NLST results will be replicated. In addition, the NLST raises several issues related to screening, such as the high false-positive rate, overdiagnosis and cost. Healthcare providers and systems are now left with the question of whether the available findings should be translated into practice. We present the main reasons for implementing lung cancer screening in high-risk adults and discuss the main issues related to lung cancer screening. We stress the importance of eligibility criteria, smoking cessation programs, primary care physicians, and informed-decision making should lung cancer screening be implemented. Seven years ago, we were waiting for the results of trials. Such evidence is now available. Similar to almost all other cancer screens, uncertainties exist and persist even after recent scientific efforts and data. We believe that by staying within the characteristics of the original trial and appropriately sharing the evidence as well as the uncertainties, it is reasonable to implement a LDCT lung cancer screening program for smokers and former smokers.

Lung cancer screening overdiagnosis: reports of overdiagnosis in screening for lung cancer are grossly exaggerated

The National Lung Cancer Screening Trial (NLST) demonstrated a mortality reduction benefit associated with low-dose computed tomography (LDCT) screening for lung cancer. There has been considerable debate regarding the benefits and harms of LDCT lung cancer screening, including the challenges related to its practical implementation. One of the controversies regards overdiagnosis, which conceptually denotes diagnosing a cancer that, either because of its indolent, low-aggressiveness biologic behavior or because of limited life expectancy, is unlikely to result in significant morbidity during the patient's remainder lifetime. In theory, diagnosing and treating these cancers offer no measurable benefit while incurring costs and risks. Therefore, if a screening test detects a substantial number of overdiagnosed cancers, it is less likely to be effective. It has been argued that LDCT screening for lung cancer results in an unacceptably high rate of overdiagnosis. This article aims to defend the opposite stance. Overdiagnosis does exist and to a certain extent is inherent to any cancer-screening test. Nonetheless, the concept is less dualistic and more nuanced than it has been suggested. Furthermore, the average estimates of overdiagnosis in LDCT lung cancer screening based on the totality of published data are likely much lower than the highest published estimates, if a careful definition of a positive screening test reflecting our current understanding of lung cancer biology is utilized. This article presents evidence on why reports of overdiagnosis in lung cancer screening have been exaggerated.

The Value of Lung Cancer CT Screening: It Is All about Implementation

Hospitals have been gradually implementing new lung cancer CT screening programs following the release of the U.S. Preventive Services Task Force grade B recommendation to screen individuals at high risk for lung cancer. Policy makers have legitimately questioned whether adoption of CT screening in the community will reproduce the mortality benefits seen in the National Lung Screening Trial (NLST) and whether the benefits of screening will justify the potentially high costs. Although three annual CT screening exams proved cost-effective for the patient population enrolled in the NLST, uncertainty still exists about whether CT screening will be cost-effective in practice. The value of CT screening will depend largely on the strategies used to implement it. This manuscript reviews the current reimbursement policies for CT screening and explains the relationship between implementation strategies and screening value on the basis of the NLST cost-effectiveness analysis and other published data. A subsequent discussion ensues about the potential implementation inefficiencies that can negatively affect the value of CT screening (e.g., selection of low-risk individuals for screening, inappropriate follow-up visits for screening-detected lung nodules, failure to offer smoking cessation interventions, and overuse of medical resources for clinically irrelevant incidental findings) and the actions that can be taken to mitigate these inefficiencies and increase the value of screening.

Geographic variation in radiologist capacity and widespread implementation of lung cancer CT screening

BACKGROUND

Newly released United States Preventive Services Task Force (USPSTF) recommendations for lung cancer screening are expected to increase demand for low-dose computed tomography scanning, but health system capacity constraints might threaten the scale-up of screening.

OBJECTIVES

To estimate the prevalence of capacity constraints in the radiologist workforce and resulting potential disparities in access to lung cancer screening.

METHODS

We combined information from health interview surveys to estimate the numbers of smokers who meet the USPSTF eligibility criteria, and information from administrative datasets to estimate the numbers of radiologists and the numbers of scans they currently interpret in Health Service Areas (HSAs) nationwide. We estimated and mapped the prevalence of capacity constrained HSAs - those having a greater than 5% or greater than 25% projected increase in scans over current levels from scaling up screening - and used descriptive statistics and logistic regressions to identify HSA characteristics associated with capacity constraints.

RESULTS

Scaling up lung cancer screening would increase imaging procedures by an average of 4% across HSAs. Of the 9.6 million eligible smokers, 1,023,943 lived in HSAs with increases of at least 5%. HSAs that were rural, with many eligible smokers, and disproportionately Hispanic or low-income smokers had significantly higher odds of facing capacity constraints.

CONCLUSIONS

Disparities in access to lung cancer screening appear likely unless policy makers target HSAs with few radiologists for additional resources. Radiologists should be able to absorb the workload imposed by lung cancer screening in most areas of the country.